1. Division of General Internal Medicine and Health Services Research, Department of Medicine, David Geffen School of Medicine at UCLA, and Geriatrics Research Education and Clinical Center, VA Greater Los Angeles Healthcare System, Los Angeles, California (C.A.S.)
2. Division of General Internal Medicine and Health Services Research, Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, California (A.R.)
3. Division of General Internal Medicine and Health Services Research, Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, California, and RAND Corporation, Santa Monica, California (J.N.M.)